Valve mechanisms for use with internal combustion engines

ABSTRACT

An internal combustion engine has a main cylinder and piston for receiving part of the main charge of combustible mixture for operating the engine, a subsidiary cylinder interconnected with the main cylinder by a passage, a valve controlling the passage so that part of the charge in the main cylinder passes into the subsidiary cylinder during the compression stroke of the main piston, a subsidiary piston in the subsidiary cylinder for increasing the compression of the part of the charge in the subsidiary cylinder, an additional fuel inlet to the subsidiary cylinder and a control mechanism for operating the valve, subsidiary piston and fuel inlet in timed relation.

United States Patent VALVE MECHANISMS FOR USE WITH INTERNAL COMBUSTION ENGINES 10 Claims, 1 Drawing Fig.

US. Cl. 123/32, 123/32C, I23/32K, l23/33VC Int. Cl. ..F02m 67/00 Field of Search 123/32,

32.2, 32.3, 32.4, 32.5, 32 (Y), 33, 33 (VC), 33 (D), 143, 143 (A) Primary Examiner-Laurence M. Goodridge AttorneyWatson, Cole, Grindle & Watson ABSTRACT: An internal combustion engine has a main cylinder and piston for receiving part of the main charge of combustible mixture for operating the engine, a subsidiary cylinder interconnected with the main cylinder by a passage, a valve controlling the passage so that part of the charge in the main cylinder passes into the subsidiary cylinder during the compression stroke of the main piston, a subsidiary piston in the subsidiary cylinder for increasing the compression of the part of the charge in the subsidiary cylinder, an additional fuel inlet to the subsidiary cylinder and a control mechanism for operating the valve, subsidiary piston and fuel inlet in timed relation.

'IIIIIIIIIIIIII Patented May 25, 1971 VALVE MECHANISMS FOR USE WITH INTERNAL COMBUSTION ENGINES The invention relates to valve mechanisms for use with internal combustion engines and particularly to piston and cylinder devices including valve mechanisms for controlling the flow of combustible mixture.

The invention provides a piston and cylinder device for an internal combustion engine comprising a main cylinder and cooperating main piston for receiving at least part of the main charge of combustible mixture for operating the engine, a subsidiary cylinder interconnected with the main cylinder by a passage, a valve controlling said passage so that part of the charge in the main cylinder passes into the subsidiary cylinder during the compression stroke of the main piston, a subsidiary piston in said subsidiary cylinder for increasing the compression of the part of the charge in the subsidiary cylinder and means for supplying additional fuel to the subsidiary cylinder.

The subsidiary cylinder may be located at one end of the main cylinder with said passage extending through the end faces of the main and subsidiary cylinders.

Preferably the said valve member includes a closure member arranged to cooperate with a valve seat at the end of the subsidiary cylinder adjacent the main cylinder and a valve stem extending through a passage in the subsidiary piston.

Preferably the end of the subsidiary cylinder adjacent the main cylinder is conical in shape. Preferably the face of the subsidiary piston which faces said end of the subsidiary cylinder is also conical in shape.

Preferably the fuel inlet to the subsidiary cylinder is arranged parallel to the conical end face of the subsidiary cylinder and is directed towards said passage.

Preferably control mechanism is provided for controlling the time of operation of the said valve, subsidiary piston and fuel inlet to the subsidiary cylinder so that the said valve is open during part of the compression stroke of the main piston and then closes, the subsidiary piston then moves through its compression stroke while the main piston completes its compression stroke, the fuel inlet then admits additional fuel to the compressed charge in the subsidiary cylinder and then on ignition of the charge in the subsidiary cylinder, the said valve opens again.

Preferably an inlet valve for the main cylinder is also controlled by said control mechanism.

The invention includes an internal combustion engine having one or more piston and cylinder devices as aforesaid.

Reference is now made to the accompanying diagram which illustrates part of an internal combustion engine embodying the present invention, here given by way .of example.

Part of an internal combustion engine is illustrated as comprising a main piston 11 operating in the bore of a main cylinder 12. An inlet valve 13 is shown for controlling the inflow of fuel and air mixture to the main cylinder 12. There is an exhaust valve, not shown. A valve mechanism fitted for operation in conjunction with the inlet valve 13 is indicated as having a subsidiary piston 14, slidable in a subsidiary cylinder 15, a valve member 16 and an inlet 9 for entry of a pilot charge of fuel. The valve member 16 comprises a closure member 17 and a valve stem 18 passing slidably through a sleeve 19 mounted in a central bore in the subsidiary piston 14. A valve seating 20 is provided at the end of the subsidiary cylinder for engagement by the closure member 17.

The subsidiary cylinder 15 is provided in the main cylinder head 21 and is arranged end to end and parallel with the main cylinder 12. A passage 22 interconnects the end faces 23 and 24 of the two cylinders. The end face 23 of the cylinder 15 is conical in shape as is the lower face 25 of the piston 14. The fuel inlet 9 is arranged parallel to the conical end face 23 of the cylinder 15 and is directed towards the passage 22. Both the pistons 14 and 11 have piston rings 26. The piston 14 is urged towards the end face 23 of the cylinder 15 by a helical compression spring 27 located between the upper end of the sleeve 19 and a fixed support 28.

The inlet valve 13, piston member 14, valve member 16 and fuel inlet 9 are operated from the engine valve gear shown diagrammatically at 30 in timed sequence. The engine valve gear 30 is connected to the main piston 11 byan operative link shown diagrammatically at 31. The inlet valve 13, piston 14, valve member 16 and fuel inlet 9 are shown with operative links 32, 33, 34 and 35 respectively, to the valve gear 30.

With a four cycle engine, piston 11 has, during its suction stroke, inhaled a mixture of air and fuel into cylinder 12. During this stroke, valve 16 is open off its seating 20, and piston 14 is retracted to the upper limit of its stroke. On its compression stroke piston 11 moves up with piston 14 still in its upper position and valve 16 still open, and this is designed to give a compression ratio, of about eight to one in the engine cylinder 12. When piston 11 has travelled approximately two-thirds of its upwards stroke, the compression ratio is 2.4/1 and at this point valve 16 closes. The valve gear 30 operates in dependence on the movement of the piston 11 and controls the time of closure of the valve 16.

The piston member 14 then begins to move down to compress the charge in the cylinder 15, the stroke of piston 14 being such that the final compression ratio in the cylinder 15 is above 20/1. [I may be noted that the final one-third of the motion of piston 11 upwards and the whole of the compression motion of piston member 14 are substantially coincident.

At the end of the compression stroke the main cylinder 11 is at a compression pressure based on an 8/1 compression ratio and contains an air'fuel mixture which will not self-ignite. In the cylinder 15 there is a compression ratio of above 20/ l, also with a mixture strength which is not self-ignitable. At this point a small pilot charge of fuel is injected through the inlet 9. This causes ignition to begin in the part of the cylinder 15 between piston member 14 and valve seating 20.

At this point valve 16 opens off its seating 20. Flame enters the main cylinder 11 and ignites the charge which is there present.

It may be noted that the maximum pressure in the main chamber 11 resulting from combustion will be no greater than that of a conventional spark ignition engine. Although the pressure in the part of the charge in the cylinder 15, on which bears the compressor piston member 14, is relatively high, the diameter of the cylinder 15 is relatively small so that the operating gear for it can be readily designed within safe stress limits.

The control valve member 16 which operates at relatively high temperature may be formed from a nickel molybdenum alloy.

It will be appreciated that the internal combustion engine may have a number of main cylinders 12 each having an associated subsidiary cylinder 15. The main charge of combustible mixture will be fed to all the main cylinders.

lt will be seen that the above example enables a dual compression mode of operation to be attained in an internal combustion engine while retaining a relatively simplified form for the main piston 11.

1 claim:

1. A piston and cylinder device for an internal combustion engine comprising a main cylinder, a main piston cooperative therein, fuel introduction means to introduce into the cylinder a main charge of combustible mixture for operating the engine, a subsidiary cylinder, a passageway interconnecting the main cylinder and the subsidiary cylinder, a valve operable to open and close said passageway, a piston cooperable with the subsidiary cylinder, fuel injection means for supplying additional fuel to the subsidiary cylinder, and means to operate the valve, the subsidiary piston and the fuel injection means in timed relation to the main piston, so that during the compression stroke a part of the main charge enters the subsidiary cylinder after which the valve is closed, the part of the charge is compressed by the subsidiary piston, the fuel injection means injects fuel into the subsidiary cylinder to ignite the charge and then the valve is openedto ignite the charge in the main cylinder.

2. A piston and cylinder device as claimed in claim 1 in which the timing of the means to operate the valve and the subsidiary piston, and the compression in the subsidiary cylinder are such that the pressure therein is raised to a sufficient level to cause ignition of the part of the charge when the fuel injection means injects fuel into the subsidiary cylinder.

3. A piston and cylinder device as claimed in claim 2 in which the subsidiary cylinder is located at one end of the main cylinder with said passage extending through the end faces of the main and subsidiary cylinders.

4. A piston and cylinder device as claimed in claim 3 in which the said valve member includes a closure member arranged to cooperate with a valve seat at the end of the subsidiary cylinder adjacent the main cylinder and a valve stem extending through a passage in the subsidiary piston.

5. A piston and cylinder device for an internal combustion engine comprising a main cylinder and cooperating main piston for receiving at least part of the main charge of combustible mixture for operating the engine, a subsidiary cylinder located at one end of the main cylinder and interconnected with the main cylinder by a passage, the end of the subsidiary cylinder adjacent to the main cylinder being conical in shape, a valve controlling said passage so that part of the charge in the main cylinder passes into the subsidiary cylinder during the compression stroke of the main piston, a subsidiary piston in said subsidiary cylinder for increasing the compression of the part of the charge in the subsidiary cylinder and means for supplying additional fuel to the subsidiary cylinder.

6. A piston and cylinder device as claimed in claim 5 in which the face of the subsidiary piston which faces said end of the subsidiary cylinder is also conical in shape.

7. A piston and cylinder device as claimed in claim 5 in which the fuel inlet to the subsidiary cylinder is arranged parallel to the conical end face of the subsidiary cylinder and is diverted towards said passage.

8. A piston and cylinder device as claimed in claim 5 in which control mechanism is provided for controlling the time of operation of the said valve, subsidiary piston and fuel inlet to the subsidiary cylinder so that the said valve is open during part of the compression stroke of the main piston and then closes, the subsidiary piston then moves through its compression stroke while the main piston completes its compression stroke, the fuel inlet then admits additional fuel to the compressed charge in the subsidiary cylinder and then on ignition of the charge in the subsidiary cylinder, the said valve opens again.

9. A piston and cylinder device as claimed in claim 8 in which an inlet valve for the main cylinder is also controlled by said control mechanism.

10. An internal combustion engine including a piston and cylinder device as claimed in claim I. 

1. A piston and cylinder device for an internal combustion engine comprising a main cylinder, a main piston cooperative therein, fuel introduction means to introduce into the cylinder a main charge of combustible mixture for operating the engine, a subsidiary cylinder, a passageway interconnecting the main cylinder and the subsidiary cylinder, a valve operable to open and close said passageway, a piston cooperable with the subsidiary cylinder, fuel injection means for supplying additional fuel to the subsidiary cylinder, and means to operate the valve, the subsidiary piston and the fuel injection means in timed relation to the main piston, so that during the compression stroke a part of the main charge enters the subsidiary cylinder after which the valve is closed, the part of the charge is compressed by the subsidiary piston, the fuel injection means injects fuel into the subsidiary cylinder to ignite the charge and then the valve is opened to ignite the charge in the main cylinder.
 2. A piston and cylinder device as claimed in claim 1 in which the timing of the means to operate the valve and the subsidiary piston, and the compression in the subsidiary cylinder are such that the pressure therein is raised to a sufficient level to cause ignition of the part of the charge when the fuel injection means injects fuel into the subsidiary cylinder.
 3. A piston and cylinder device as claimed in claim 2 in which the subsidiary cylinder is located at one end of the main cylinder with said passage extending through the end faces of the main and subsidiary cylinders.
 4. A piston and cylinder device as claimed in claim 3 in which the said valve member includes a closure member arranged to cooperate with a valve seat at the end of the subsidiary cylinder adjacent the main cylinder and a valve stem extending through a passage in the subsidiary piston.
 5. A piston and cylinder device for an internal combustion engine comprising a main cylinder and cooperating main piston for receiving at least part of the main charge of combustible mixture for operating the engine, a subsidiary cylinder located at one end of the main cylinder and interconnected with the main cylinder by a passage, the end of the subsidiary cylinder adjacent to the main cylinder being conical in shape, a valve controlling said passage so that part of the charge in the main cylinder passes into the subsidiary cylinder during the compression stroke of the main piston, a subsidiary piston in said subsidiary cylinder for increasing the compression of the part of the charge in the subsidiary cylinder and means for supplying additional fuel to the subsidiary cylinder.
 6. A piston and cylinder device as claimed in claim 5 in which the face of the subsidiary piston which faces said end of the subsidiary cylinder is also conical in shape.
 7. A piston and cylinder device as claimed in claim 5 in which the fuel inlet to the subsidiary cylinder is arranged parallel to the conical end face of the subsidiary cylinder and is diverted towards said passage.
 8. A piston and cylinder device as claimed in claim 5 in which control mechanism is provided for controlling the time of operation of the said valve, subsidiary piston and fuel inlet to the subsidiary cylinder so that the said valve is open during part of the compression stroke of the main piston and then closes, the subsidiary piston then moves through its compression stroke while The main piston completes its compression stroke, the fuel inlet then admits additional fuel to the compressed charge in the subsidiary cylinder and then on ignition of the charge in the subsidiary cylinder, the said valve opens again.
 9. A piston and cylinder device as claimed in claim 8 in which an inlet valve for the main cylinder is also controlled by said control mechanism.
 10. An internal combustion engine including a piston and cylinder device as claimed in claim
 1. 